Additional Commentary
Yes, these stumpy whiz bang new cartridges really do spit their bullets out considerably faster than the more garden variety traditional calibers, whether one compares factory or handloaded ammo. On this point, there is no question - show me a handloader hot rodding an .270 winchester, and I'll show you a hot rodder handloading a "stumpy" just that much faster!!
Keep in mind that when you drive a given bullet faster, you stress the design envelope of the bullet.
A .270 win works wonderfully on our more common north american ungulate critters using even the low cost and widely available winchester power point ammo.
Up the velocity by 200 - 300 fps, and those common low cost softer bullets may well break up on heavy bone.......
So, if you wanna drive bullets hard, then better be using premium ammo with controlled expansion bullets such as Barnes X, Nosler partitions, or one of the newer bonded core bullets such as accubonds, or scirroccos. Shot placement will ALWAYS be key. A .270 winchester will kill moose with nice broadside shots, but may struggle to get to the boiler room on less than ideal shot angles. I saw this play out in Geraldton 15 years ago where a hunting companion killed a moose with a .270 winchester at about 150 yards using a typical bullet of the time (winchester silvertips), but did swat that moose (too)many times on a head-on angle before it finally fell over. On the other hand, I shot a good size whitetail facing dead away from me on Manitoulin island 4 years ago with a .270 win at 165 lasered yards with a 130 grain Swift scirocco where the bullet hit the rear ham, ran up the inside of the rib cage and exited through a small fist sized hole in the centre of the brisket.
In the end, buy what yanks your crank...... think about how long your shots will truly be, look at whether you care about ammo cost, availability, or if it's more important to have a rifle with a short action vs longer standard action, and whether you wish to up the recoil ante and whether you have the patience and skill to pick your shots carefully. Tomato or tomatoe?